# [[Automation and Robotics Glossary]] ## APC – Advanced Process Control ## cobot – collaborative robot A collaborative robot doesn't refer to a specific robot configuration but rather it's ability to have human collaborators. A 6-axis robot arm ^[the 6-axis / 6DOF articulated arm is what most people think about when they think about an industrial robot] is the most common configuration for a collaborative robot ^[[The Basics of 6-Axis, SCARA, Delta and Collaborative Robots – cross](https://www.crossco.com/resources/technical/robotics-101-6-axis-vs-scara-vs-delta-vs-collaborative/)] ^[Robot ROI [What is the Average Price of a Collaborative Robot Robot - robotiq](https://blog.robotiq.com/what-is-the-price-of-collaborative-robots)] ## End-effector a.k.a robot end-of-arm tooling The tool or device at the end of the robot arm that interacts with the environment. While you can choose from numerous end-effectors for different applications, they aren't easily swap-able in the way you might quickly changes milling tools on a [[Computer numerical control | CNC]] mill since a robot arm end-effector can change the properties of the robot's motion. They're usually configured once per application during commissioning. For reasoning about the kinematics, coordinate frame for a 6DOF robot arm (Trans(x,y,z) and Rot(x,y,z)) are usually with reference to a fix datum at the center of the base of the robot ## IK – Inverse Kinematics Working from the goal position and orientation of an end effector, work backwards and solve for the angles of each joint in a multi-joint robot arm. ^[Forwards and Backwards Reaching Inverse Kinematics FABRIK is an iterative heuristic method (heuristic $=$ best guess method) for IK that's pretty easy to understand – [FABRIK (Inverse kinematics)](https://www.youtube.com/watch?v=UNoX65PRehA)] ## Light Curtain A basic safety feature of fenced off robotic areas usually created by installing led / laser photo-gates that trip a safety PLC e-stop placed at the human operator can ingress / egress points in the safety fence where the equipment is operating. Vision systems are an alternative safety mechanism. ## OLRP – Offline Robotics Programming Software tools and languages and sims that allow programming a robot offline (as opposed to "online" programming where you're teaching a robot the motion paths once it's been installed for an application). ## PAC – Programmable Automation Controller Rather than a micro-controller, this is a full-fledged PC running the real-time micro-controller PLC logic in software. The term seems to have originated around 2001 out of the [ARC Advisory Group](https://www.arcweb.com/) who defined a PAC to have the following characteristics: > - Multi-domain functionality (e.g. motion control, process control, sequential control and communication) > - Single, multi-discipline development platform > - Flexibility software that to maximize process flow across machines or processes > - Open, modular architecture > - Compatibility with enterprise networks The line between [[PLC]] and a [[PAC]] continues to get blurrier as PLCs continue to gain capability but PACs tend to still have a more modular (expandable) design and can handle large numbers of complex, high-speed analog I/O ^[https://www.motioncontroltips.com/when-to-use-a-programmable-automation-controller-pac/] which makes PACs well suited for complex vision applications (e.g. vision guided motion control). Some people just toss up the distinction to marketing / consulting jargon to artificially differentiate advanced PLCs. [^plc-vs-pac] ## PLC – Programmable Logic Controller Created in the early 60s to replace relay-based systems. Typically PLCs are suited for machine control driven by program execution scans, limited memory and discrete I/O (on/off control). Traditionally, PLCs couldn't easily handle things outside of their intended design space, eg analog IO or sophisticated data computation had to be offloaded to other mechanisms. This lack of functionality gave rise to a desire to integrate different modes in the same control device, the a PAC [^plc-vs-pac] ## RTU – Remote Terminal Unit ## SCADA – Supervisory Control and Data Acquisition SCADA refers to a type of control system architecture rather than a specific piece of software. ## SCARA – Selective Compliant Assembly Robot a.k.a. selective compliant articulated robot arm A type of robot arm that's used in similar applications as Cartesian or gantry system (think 3D printer). - https://www.robots.com/blogs/which-is-better-scara-vs-cartesian-robots ## Teach pendant / Tech box A hand held graphical control used to program a robots motions when it's in "learning" or "teach mode". Even with the advent of offline robotics programming (OLRP), it's still common to need to tweak the program during commissioning. ## References - [The Basics of 6-Axis, SCARA, Delta and Collaborative Robots](https://www.crossco.com/resources/technical/robotics-101-6-axis-vs-scara-vs-delta-vs-collaborative/) - [What's the price of collaborative and industrial robots](https://blog.robotiq.com/what-is-the-price-of-collaborative-robots) [^plc-vs-pac]: https://www.controleng.com/articles/plc-vs-pac/ --- - Links: [[Industrial Control System]] [[Process Control]] [[Robotics]] - Created at: [[2021-04-04]]